1. Field of the Invention
The present invention relates generally to modeling subterranean features and more particularly to analysis of seismic data using probabilistic comparisons between the data and modeled seismic data.
2. Description of the Related Art
Seismic data acquisition is the most common means to get information about subsurface features. Commonly, acoustic signals are successively generated at a set of regular grid points and reflected signals, resulting from interfaces between subterranean features having different elastic properties are recorded via detectors positioned at or below the surface. Typically, the detectors are similarly arranged in a regular grid, which may coincide with the grid of source locations. The signal recorded by a detector is called a seismic trace. The seismic traces are then sorted into gathers, possibly after some preliminary processing, such that traces in a specific gather represent reflections from about the same subsurface reflection point. Hence, each trace in such a Common Reflection Point gather has a different source and has been recorded by a different receiver. It is usually identified by the geographic location of the reflection point and by the distance (offset) between the source and the detector. Because reflection amplitudes depend on the angle at which a signal impinges on an interface, and because this angle depends on the source-detector offset, the reflection amplitudes are offset-dependent. The offset (or angle-of-incidence) dependence can be exploited to determine properties of rocks in the subsurface region.